I've read only a tiny bit on this but had to burn some tree tops after having some large trees removed and decided to try it. I'm not sure if I'm going about it the right way. I had a huge stack of p-stems and covered them with the hot coals from my burning. I also covered this with ash and sawdust(wood shavings). The pile has been reduced significantly. I added some of the greener ones to the top for now.